Suppose that $a$ is inversely proportional to $b$.  Let $a_1,a_2$ be two nonzero values of $a$ such that $\frac{a_1}{a_2}=\frac{2}{3}$.  Let the corresponding $b$ values be $b_1,b_2$.  If $b_1,b_2$ are nonzero, find the value of $\frac{b_1}{b_2}$.
Solution: If $a$ is inversely proportional to $b$, then the product $ab$ is a constant.  For $a_1$ and $a_2$ this implies: $$a_1\cdot b_1=a_2\cdot b_2$$We can divide both sides of this equation by $b_1\cdot a_2$ to find: \begin{align*}
\frac{a_1\cdot b_1}{b_1\cdot a_2}&=\frac{a_2\cdot b_2}{b_1\cdot a_2}\\
\Rightarrow\qquad \frac{2}{3}=\frac{a_1}{a_2}&=\frac{b_2}{b_1}\\
\Rightarrow\qquad \boxed{\frac{3}{2}}&=\frac{b_1}{b_2}
\end{align*}